Project Summary/Abstract An estimated 13 million people in the US have latent tuberculosis (TB) infection (LTBI) and act as reservoirs from which deadly active TB disease can develop. Of the total number of TB cases reported nationally in 2017, non-US-born persons accounted for approximately of 70.1%; however, the disproportion is even greater in Orange County, California, where non-US-born persons accounted for approximately 89.2%. A recent study of TB among non-US-born residents found 58.6% of TB cases were from permanent residents, indicating a significant missed opportunity for LTBI intervention in the immigration process. A population that can be screened and treated to reduce the incidence of LTBI is ?green? card applicants (GCAs) seeking a change in status from temporary to permanent US residency. GCAs are already procedurally screened for LTBI through medical examination made mandatory by U.S. Citizenship and Immigration Services. The Centers for Disease Control and Prevention (CDC) released new guidelines that may provide favorable opportunities to ensure LTBI-positive GCAs are provided with evidence-based treatment. With the release of the new guidelines, there are many gaps in knowledge, particularly the effect these guidelines will have on GCAs and civil surgeons. It is crucial to screen and treat LTBI in non-US-born persons to reduce disparities in TB morbidity and mortality and, consequently, to achieve TB elimination in the US. This study will contribute to the current knowledge base about the reach and implementation fidelity of the new guidelines through the following aims: 1) to determine civil surgeons? adherence to new CDC guidelines, specifically the percentage of civil surgeons who screen using a blood test, report LTBI-positive GCAs to the health department, and inform GCAs of their LTBI diagnosis; 2) to determine the effect of the implementation of new CDC guidelines on LTBI treatment rates among GCAs; and 3) to explore facilitators and potentially modifiable barriers to guideline adherence among civil surgeons. We will generate critical preliminary data for developing public health outreach programs to maximize the uptake of the new guidelines and, ultimately, prevent TB among GCAs. As TB screening is already routinely done in this population, focusing on extending LTBI treatment services to GCAs may be a sustainable strategy that substantially contributes to TB elimination in the US. This fellowship training will take place at the University of California-Irvine and will enable the applicant to achieve the following goals: 1) mastery of skills for quantitative research, specifically in research design, statistical analysis, and survey building; 2) mastery of skills for qualitative research, specifically in qualitative study design, fieldwork analysis, data collection, interview techniques, content analysis, and write-up of qualitative data; 3) expand knowledge of theories, models, and frameworks of implementation science; and 4) engagement in health disparities, migrant health, and community-based research.